Which is incorrect for genetic code?
(i) The codon is triplet
(ii) 64 codons code for amino acids
(iii) Genetic code is unambigous
(iv) Genetic code is nearlyuniversal
(v) Genetic code dual functions

Options

A. only (ii)
B. (ii) & (iii)
C. (iii), (iv), (v)
D. All are correct

Answer

To determine which statement about the genetic code is incorrect, we will analyze each option step by step.

### Step-by-Step Solution:

1. **Understanding Codons**:
- The genetic code is made up of codons, which are sequences of three nucleotides (triplets).
- **Statement (i)**: "The codon is triplet" is **correct**.

2. **Counting Codons**:
- There are a total of 64 possible codons formed from the four nucleotides (A, U, C, G).
- However, not all of these codons code for amino acids. Out of the 64, 61 codons code for amino acids, while 3 are stop codons.
- **Statement (ii)**: "64 codons code for amino acids" is **incorrect** because only 61 codons actually code for amino acids.

3. **Unambiguous Nature of Genetic Code**:
- Each codon specifies only one amino acid, which means the genetic code is unambiguous.
- **Statement (iii)**: "Genetic code is unambiguous" is **correct**.

4. **Universality of Genetic Code**:
- The genetic code is nearly universal, meaning it is the same across most organisms, although there are some exceptions in certain organisms.
- **Statement (iv)**: "Genetic code is nearly universal" is **correct**.

5. **Dual Functions of Genetic Code**:
- The genetic code primarily serves to code for amino acids and to translate genetic information. However, the term "dual functions" may be misleading as it is not a standard term used to describe the genetic code.
- **Statement (v)**: "Genetic code dual functions" is somewhat ambiguous, but it can be interpreted as **correct** in the context of coding and translating.

### Conclusion:
The incorrect statement regarding the genetic code is **(ii)**: "64 codons code for amino acids".